1. Field of Invention
This invention pertains to an anti-rotation mechanism that has infinitely variable steps for a ratchet-like operation, for example, a socket wrench.
2. Description of the Related Art
A wrench is a tool used to grip and provide mechanical advantage in applying torque to a fastener. A common type of wrench is a ratchet wrench, which allows rotary motion in one direction while inhibiting motion in the opposite direction. A ratchet wrench uses a gear and a pawl to control the rotary motion. The teeth of the gear define the minimum angular rotation of the wrench when in operation.
Other types of wrenches besides those using ratchets are known. For example, U.S. Pat. No. 6,055,888 discloses a wrench device with a bearing-type clutch for selectively and reversibly providing a unidirectional rotational force and an opposite unidirectional independent rotation. The wrench device includes one or more bearings disposed in an irregular space between a primary wall of a primary body and a secondary wall of a secondary body. The space has tapering or narrowing sections in which the bearings bind to fixedly engage the primary and secondary bodies as the primary body rotates in a first rotational direction. A pin or toggle dislodges a bearing so that the primary body may rotate freely in a second, opposing rotational direction while another bearing binds the secondary body to the primary body when said primary body is rotated in the first rotational direction. Alternatively, a bearing is selectively positioned in the space to cause the primary and secondary to rotate together or independently depending on the positioning of the bearing and the rotational direction of the primary body.
U.S. Pat. No. 6,367,354 was filed as a continuation-in-part application of U.S. Pat. No. 6,055,888. U.S. Pat. No. 6,367,354 identifies a problem with bearing-type wrenches, which is that they may roll under high torque conditions. The roller bearings of wrenches of the type disclosed in U.S. Pat. No. 6,055,888 inhibit rotation at the expense of applying an outward force to the wrench housing. Under high toque conditions, the outward force is sometimes sufficient to deform the wrench housing sufficiently to allow the bearing to move or slip.